The present invention relates to printed circuit boards. More particularly, the present invention relates to a power connection structure for printed circuit boards.
DC modules connected to printed circuit boards (PCB) have increasingly required higher current outputs. The connection from the PCB to the output pins can fail to provide an adequate path for the total current to transfer to the PCB without damaging it at the point of connection. Increasing the copper connections from these output pins to the PCB will solve the need for an increased current path. But at the same time, the additional copper inhibits the flow of solder due to the heat wicking effect of the increased copper area during the assembly process which will cause the upper layers of the PCB to have no connection at all to the output pins of the module.
FIG. 1 illustrates a PCB 100 having a power connection structure receiving a pin of a power supply module (not shown) according to a prior art. The PCB 100 has a top layer 102, several intermediate layers 104, and a bottom layer 106. FIG. 1 illustrates a PCB having four intermediate layers. A plated through hole 108 disposed through all layers 102, 104, and 106 mate with the pin of the power supply module.
FIG. 2 illustrates a cross-sectional view of a PCB 200 receiving a pin 202 of a power supply module 204 according to a prior art. A plated through hole 206 received the pin 202. Solder 208 connects the pin 202 to the plating 210 of the plated through hole 206. The pin 202 is coupled to the PCB 200 through solder 208 and the plating 210. However during reflow process, the thermal mass from all the inner layers 212 draws heat from solder 208 and prevents solder 208 from reaching the top layer 214 of the PCB 200.
Therefore, a solder fill may at most reach the second or third layer, rendering the connection inefficient and potentially faulty. It would be desirable to provide a power connection structure for a PCB capable of carrying high current outputs while preventing a heat wicking effect of the copper area due to high current, thereby saving costs and board space.
A multi-layer printed circuit board (PCB) has a plated through hole for receiving a pin of a component. The plated through hole passes through all layers of the PCB and includes a first conductive portion on a first surface of the PCB and a second conductive portion on a second surface of the PCB. At least one layer of the PCB includes a planar conductive material disposed over a planar insulating material. The conductive material surrounds the plated through hole and is separated therefrom by a gap.